Color correction for radiation detectors

• US 8,153,980 B1
• Filed: 11/30/2006
• Issued: 04/10/2012
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Brady, John F., Syllaios, Athanasios J., Schimert, Thomas R., McCardel, William L., Gooch, Roland W.
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Bryant, Casey
• Application Number:
  US11/607,122
• Time in Patent Office: 1,958 Days
• Field of Search: 250/338.1, 250/338.4, 250/339.05, 250/339.06
• US Class Current: 250/350
• CPC Class Codes: G01J 2003/1213 Filters in general, e.g. dichroic, band
• CPC Class Codes: G01J 3/0232 using shutters
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 5/0804 Shutters
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices

Abstract

Systems and methods for color correcting radiation by alternately focusing a first radiation spectrum on a first radiation spectrum detector, and then focusing at least one additional radiation spectrum on at least one additional radiation spectrum detector.

Claims

1. A color-corrected radiation detection system, comprising:

a first radiation spectrum detector capable of detecting at least a first radiation spectrum and a second radiation spectrum detector capable of detecting at least a second radiation spectrum, said first and second radiation spectra being different; and

a color-correcting chopper positioned between said first and second radiation spectrum detectors and a source of said first radiation spectrum and said second radiation spectrum, said color-correcting chopper having at least a first portion and a second portion, said first portion being configured to focus said first radiation spectrum on said first radiation spectrum detector and said second portion being configured to focus said second radiation spectrum on said second radiation spectrum detector.

2. The radiation detection system of claim 1, wherein said first and second radiation spectrum detectors are integrated together into a multi-band detector element.

3. The radiation detection system of claim 2, wherein said first and second radiation spectrum detectors are integrated together as part of a multi-band focal plane array (FPA).

4. The radiation detection system of claim 3, wherein said first radiation spectrum detector comprises visible imaging circuitry configured to detect visible radiation;

and wherein said second radiation spectrum detector comprises an infrared radiation detector structure configured to absorb infrared radiation.

5. The radiation detection system of claim 1, wherein said first radiation spectrum detector comprises visible imaging circuitry configured to detect visible radiation;

and wherein said second radiation spectrum detector comprises an infrared radiation detector structure configured to absorb infrared radiation.

6. The radiation detection system of claim 5, wherein said first radiation spectrum comprises visible radiation and said second radiation spectrum comprises infrared radiation;

wherein said first portion of said color-correcting chopper is open to allow said visible radiation and said infrared radiation to pass through said color-correcting chopper so that said visible radiation is focused on said visible imaging circuitry and so that said infrared radiation is defocused on said infrared radiation detector structure; and

wherein said second portion of said color-correcting chopper comprises a material that is opaque to said visible radiation and focuses infrared energy on said infrared radiation detector structure.

7. The radiation detection system of claim 1, wherein said first portion of said color-correcting chopper comprises a material having a first thickness that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a material having a second thickness that focuses energy of said second spectrum on said second radiation spectrum detector;

wherein said material of said first portion is the same as said material of said second portion; and

wherein said first thickness is different than said second thickness.

8. The radiation detection system of claim 1, wherein said first portion of said color-correcting chopper comprises a first material that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a second material that focuses energy of said second spectrum on said second radiation spectrum detector; and

wherein said first material is different from said second material.

9. The radiation detection system of claim 1, wherein said first portion of said color-correcting chopper is open to allow all energy to pass through said color-correcting chopper;

and wherein said second portion of said color-correcting chopper comprises a material that focuses energy of said second spectrum on said second radiation spectrum detector.

10. The radiation detection system of claim 1, further comprising:

a third radiation spectrum detector capable of detecting at least a third radiation spectrum, said third radiation spectrum being different than each of said first and second radiation spectra;

wherein said color-correcting chopper is positioned between said first, second and third radiation spectrum detectors and a source of said first radiation spectrum, said first second radiation spectrum, and said third radiation spectrum; and

wherein said color-correcting chopper further comprises a third portion, said third portion being configured to focus said third radiation spectrum on said third radiation spectrum detector.

11. The radiation detection system of claim 10, further comprising:

a fourth radiation spectrum detector capable of detecting at least a fourth radiation spectrum, said fourth radiation spectrum being different than each of said first, second and third radiation spectra;

wherein said color-correcting chopper is positioned between said first, second third and fourth radiation spectrum detectors and a source of said first radiation spectrum, said first second radiation spectrum, said third radiation spectrum, and said fourth radiation spectrum; and

wherein said color-correcting chopper further comprises a fourth portion, said fourth portion being configured to focus said fourth radiation spectrum on said fourth radiation spectrum detector.

12. The radiation detection system of claim 1, further comprising

one or more optical elements configured to be positioned between said first and second radiation spectrum detectors and the source of said first radiation spectrum and said second radiation spectrum, the one or more optical elements being configured to provide energy of the first radiation spectrum focused at a different location than the energy of the second radiation spectrum and to provide energy of the second radiation spectrum that is defocused on the second radiation spectrum detector;

where the color-correcting chopper is positioned between said first and second radiation spectrum detectors and the one or more optical elements, said color-correcting chopper having at least a first portion and a second portion, said first portion being configured to provide energy of said first radiation spectrum that is focused on said first radiation spectrum detector and said second portion being configured to receive and correct the focus of the energy of the second radiation spectrum from the one or more optical elements so as to provide energy of said second radiation spectrum that is focused on said second radiation spectrum detector.

13. The system of claim 12, where the first portion of the color-correcting chopper is configured to correct an optical path of the first radiation spectrum to focus said first radiation spectrum on said first radiation spectrum detector, or where second portion of the color-correcting chopper is configured to correct an optical path of the second radiation spectrum to focus said second radiation spectrum on said second radiation spectrum detector, or a combination thereof.

14. The system of claim 13, where the first radiation spectrum comprises visible radiation;

where the second radiation spectrum comprise infrared radiation;

where the first radiation spectrum detector and the second radiation spectrum detector are in the same focal plane; and

where the first portion of the color-correcting chopper is configured to focus said visible spectrum on the focal plane of the first and second radiation spectrum detectors; and

where the second portion of the color-correcting chopper is configured to focus said infrared spectrum on the focal plane of the first and second radiation spectrum detectors.

15. A color-correction method comprising alternately placing a first portion of a color-correcting chopper between first and second radiation spectrum detectors and a source of a first radiation spectrum and a second radiation spectrum to focus a first radiation spectrum on said first radiation spectrum detector, and then placing a second portion of said color-correcting chopper between said first and second radiation spectrum detectors and said source of said first radiation spectrum and said second radiation spectrum to focus said second radiation spectrum on said second radiation spectrum detector;

wherein said first and second radiation spectra are different.

16. The method of claim 15, further comprising:

providing and positioning a multi-band detector element to receive said first radiation spectrum and said second radiation spectrum from a common optical train, said first and second radiation spectrum detectors being integrated together as part of a multi-band detector element; and

simultaneously receiving said first radiation spectrum and said second radiation spectrum from said common optical train at said multi-band detector element.

17. The method of claim 16, further comprising providing said first and second radiation spectrum detectors integrated together as part of a multi-band focal plane array (FPA).

18. The method of claim 17, wherein said first radiation spectrum detector comprises visible imaging circuitry configured to detect visible radiation;

and wherein said second radiation spectrum detector comprises an infrared radiation detector structure configured to absorb infrared radiation.

19. The method of claim 15, wherein said first radiation spectrum detector comprises visible imaging circuitry configured to detect visible radiation;

and wherein said second radiation spectrum detector comprises an infrared radiation detector structure configured to absorb infrared radiation.

20. The method of claim 19, wherein said first radiation spectrum comprises visible radiation and said second radiation spectrum comprises infrared radiation;

wherein said first portion of said color-correcting chopper is open to allow said visible radiation and said infrared radiation to pass through said color-correcting chopper so that said visible radiation is focused on said visible imaging circuitry and so that said infrared radiation is defocused on said infrared radiation detector structure; and

wherein said second portion of said color-correcting chopper comprises a material that is opaque to said visible radiation and focuses infrared energy on said infrared radiation detector structure.

21. The method of claim 15, wherein said first portion of said color-correcting chopper comprises a material having a first thickness that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a material having a second thickness that focuses energy of said second spectrum on said second radiation spectrum detector;

wherein said material of said first portion is the same as said material of said second portion; and

wherein said first thickness is different than said second thickness.

22. The method of claim 15, wherein said first portion of said color-correcting chopper comprises a first material that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a second material that focuses energy of said second spectrum on said second radiation spectrum detector; and

wherein said first material is different from said second material.

23. The method of claim 15, wherein said first portion of said color-correcting chopper is open to allow all energy to pass through said color-correcting chopper;

and wherein said second portion of said color-correcting chopper comprises a material that focuses energy of said second spectrum on said second radiation spectrum detector.

24. The method of claim 15, comprising alternately placing a first portion of a color-correcting chopper between first, second and third radiation spectrum detectors and a source of a first radiation spectrum, a second radiation spectrum and a third radiation spectrum to focus a first radiation spectrum on said first radiation spectrum detector;

then placing a second portion of said color-correcting chopper between said first, second and third radiation spectrum detectors and said source of said first radiation spectrum, said second radiation spectrum and said third radiation spectrum to focus said second radiation spectrum on said second radiation spectrum detector; and

then placing a third portion of said color-correcting chopper between said first, second and third radiation spectrum detectors and said source of said first radiation spectrum, said second radiation spectrum and said third radiation spectrum to focus said third radiation spectrum on said third radiation spectrum detector;

wherein said first, second and third radiation spectra are different.

25. The method of claim 15, comprising alternately placing a first portion of a color-correcting chopper between first, second, third and fourth radiation spectrum detectors and a source of a first radiation spectrum, a second radiation spectrum, a third radiation spectrum and a fourth radiation spectrum to focus a first radiation spectrum on said first radiation spectrum detector;

then placing a second portion of said color-correcting chopper between said first, second, third and fourth radiation spectrum detectors and said source of said first radiation spectrum, said second radiation spectrum, said third radiation spectrum and said fourth radiation spectrum to focus said second radiation spectrum on said second radiation spectrum detector;

then placing a third portion of said color-correcting chopper between said first, second, third and fourth radiation spectrum detectors and said source of said first radiation spectrum, said second radiation spectrum, said third radiation spectrum and said fourth radiation spectrum to focus said third radiation spectrum on said third radiation spectrum detector; and

then placing a fourth portion of said color-correcting chopper between said first, second, third and fourth radiation spectrum detectors and said source of said first radiation spectrum, said second radiation spectrum, said third radiation spectrum and said fourth radiation spectrum to focus said fourth radiation spectrum on said fourth radiation spectrum detector;

wherein said first, second, third and fourth radiation spectra are different.

26. The method of claim 15, further comprising:

providing the first radiation spectrum detector to be capable of detecting at least the first radiation spectrum and the second radiation spectrum detector to be capable of detecting at least the second radiation spectrum, said first and second radiation spectra being different;

providing one or more optical elements in position between said first and second radiation spectrum detectors and the source of said first radiation spectrum and said second radiation spectrum, the one or more optical elements being configured to provide energy of the first radiation spectrum focused at a different location than the energy of the second radiation spectrum and to provide energy of the second radiation spectrum that is defocused on the second radiation spectrum detector; and

alternately placing the first portion of the color-correcting chopper between the one or more optical elements and the first and second radiation spectrum detectors to provide energy of the first radiation spectrum that is focused on said first radiation spectrum detector, and then placing a second portion of said color-correcting chopper between the one or more optical elements and said first and second radiation spectrum detectors to receive and correct the focus of the energy of the second radiation spectrum from the one or more optical elements so as to provide energy of said second radiation spectrum that is focused on said second radiation spectrum detector;

wherein said first and second radiation spectra are different.

27. The method of claim 26, where the first portion of the color-correcting chopper corrects an optical path of the first radiation spectrum to focus said first radiation spectrum on said first radiation spectrum detector, or where second portion of the color-correcting chopper corrects an optical path of the second radiation spectrum to focus said second radiation spectrum on said second radiation spectrum detector, or a combination thereof.

28. The method of claim 27, where the first radiation spectrum comprises visible radiation;

where the second radiation spectrum comprise infrared radiation;

where the first radiation spectrum detector and the second radiation spectrum detector are in the same focal plane; and

where the first portion of the color-correcting chopper focuses said visible spectrum on the focal plane of the first and second radiation spectrum detectors; and

where the second portion of the color-correcting chopper focuses said infrared spectrum on the focal plane of the first and second radiation spectrum detectors.

29. A color-correcting chopper configured for placement between first and second radiation spectrum detectors and a source of a first radiation spectrum and a second radiation spectrum, said color-correcting chopper comprising:

a first portion configured to focus said first radiation spectrum on said first radiation spectrum detector; and

a second portion configured to focus said second radiation spectrum on said second radiation spectrum detector.

30. The color-correcting chopper of claim 29, wherein said first radiation spectrum comprises visible radiation and said second radiation spectrum comprises infrared radiation;

wherein said first portion of said color-correcting chopper is open to allow said visible radiation and said infrared radiation to pass through said color-correcting chopper so that said visible radiation is focused on said visible imaging circuitry and so that said infrared radiation is defocused on said infrared radiation detector structure; and

wherein said second portion of said color-correcting chopper comprises a material that is opaque to said visible radiation and focuses infrared energy on said infrared radiation detector structure.

31. The color-correcting chopper of claim 29, wherein said first portion of said color-correcting chopper comprises a material having a first thickness that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a material having a second thickness that focuses energy of said second spectrum on said second radiation spectrum detector;

wherein said material of said first portion is the same as said material of said second portion; and

wherein said first thickness is different than said second thickness.

32. The color-correcting chopper of claim 29, wherein said first portion of said color-correcting chopper comprises a first material that focuses energy of said first spectrum on said first radiation spectrum detector;

wherein said second portion of said color-correcting chopper comprises a second material that focuses energy of said second spectrum on said second radiation spectrum detector; and

wherein said first material is different from said second material.

33. The color-correcting chopper of claim 29, wherein said first portion of said color-correcting chopper is open to allow all energy to pass through said color-correcting chopper;

and wherein said second portion of said color-correcting chopper comprises a material that focuses energy of said second spectrum on said second radiation spectrum detector.

34. The color-correcting chopper of claim 29, configured for placement between first, second and third radiation spectrum detectors and a source of a first radiation spectrum, a second radiation spectrum and a third radiation spectrum, said color-correcting chopper comprising a third portion configured to focus said third radiation spectrum on said third radiation spectrum detector.

35. The color-correcting chopper of claim 29, configured for placement between first, second, third and fourth radiation spectrum detectors and a source of a first radiation spectrum, a second radiation spectrum, a third radiation spectrum and a fourth radiation spectrum, said color-correcting chopper comprising a fourth portion configured to focus said fourth radiation spectrum on said fourth radiation spectrum detector.